Features & Columns

Chinook Salmon andthe Peripheral Canal

Can California's Chinook salmon population survive plans for the Peripheral Canal?

July 3, 2012 - by Alastair Bland

FISH OUT OF WATER: The 'Peripheral Canal' project could endanger salmon runs.

Chinook salmon are abundant this year in one of the best seasons of local fishing memory, with sport and commercial fishermen reeling in easy boatloads of the most prized food and game fish on the Pacific Coast.

Still, a local conservation group warns that all this could change if state officials in Sacramento, now plotting the near future of California's water-development infrastructure, approve and build a large canal intended to deliver Sacramento River water to Southern California.

The project has been tentatively called the "Peripheral Canal" for decades, since state voters rejected a proposal to build such a conveyance structure in 1982. Opponents of the canal say the project would remove so much water from the Sacramento River that it would make the estuary habitat of the Delta, where juvenile salmon spend their first six months of life, incapable of supporting certain native fishes.

But now the "Peripheral Canal" plan is back on the drawing board of state government officials, including Gov. Jerry Brown. The Golden Gate Salmon Association, based in Petaluma, wants to see the project halted before it destroys one of the West Coast's largest runs of Chinook salmon.

"These are critical times, in the next year or two, for what the Bay-Delta and its salmon will look like for the rest of our lives," says Victor Gonella, founder and president of the Golden Gate Salmon Association. "It's a rare time. We're sitting here while our future is shaping up."

Chinook salmon spawn in many watersheds along the West Coast, as far north as Alaska's Yukon River. The Sacramento River is the southernmost stronghold of the species, but its salmon runs have seen a roller-coaster ride in the last decade between record high and record low levels. Experts largely agree that water conditions, including flow rates, of the river and Delta, where baby salmon spend their first months of life, have a direct effect on salmon abundance.

State and federal records show a long-term average spawning return of the fall-run Chinook, the most historically abundant of the Sacramento's four distinct runs of salmon, to be between 300,000 and 400,000 fish. But 2009's record low of 39,000 spawners came after water pumping rates from the Delta jumped by 20 percent, to all-time high levels, from 2003 to 2006.

Fishermen fear that the proposed canal will cause a decrease in water-flow rates, and as a result a decline in salmon numbers.

"[Gov.] Brown needs to scrap the 'Peripheral Canal' until further notice," says Mike Hudson, a commercial fisherman in Oakland. Hudson says the current fishing is as good as it's been in at least five years, but he adds that he isn't confident about the future. "Along the entire West Coast we have managed to stop overfishing. Now, if we could only stop overfarming we'd have it made."

Peter Moyle, a fisheries biologist at UC-Davis, says that the current system for water removal from the Sacramento River, which involves two giant pumps in the Delta, reverses the entire flow of the estuary system when the pumps are operating at full force. This phenomenon confuses young salmon trying to migrate out to sea, Moyle says. Many become lost or stranded in sloughs, where they make easy pickings for predators. Others are sucked directly into the pumps and killed. Moyle says the canal, which would draw water from a location far upstream of the Delta, could be beneficial for the Delta habitat since the reverse flow effect would no longer occur.

But he says that a healthy salmon population requires a minimum amount of water flowing through the Delta and out to sea.

"A conveyance in any form will be positive from a native fish perspective only if it is connected to no net increase in diversion [of water]," Moyle says.

What makes Gonella at the Golden Gate Salmon Association nervous is that current plans for the canal's construction include a 15,000-cubic-foot-per-second capacity, enough to virtually suck the Sacramento River dry. Gonella wants to see that capacity downsized, or see a guarantee written into the plans for the "Peripheral Canal" that assures recipients of the water could never turn the flow up to full.

The current surge in salmon abundance seems to come partly in response to a federal law that took effect three years ago that limits how much water can be removed from the Sacramento River Delta during the winter and spring months, when juveniles of the protected spring- and winter-run salmon are present in the Delta. The fall-run, which is not a listed species, has seen benefits from these water-restriction laws.

Still, habitat conditions in the Delta are generally so poor that baby salmon born in Sacramento's tributaries must be transported by the millions in trucks and released into the bay, downstream of the Delta and its dangerous water pumps. This trucking program, however, may be downsized due to state budget cuts, which could be a disaster for salmon numbers.

Jon Rosenfield, a conservation biologist at the Bay Institute in Novato, says that in spite of the Chinook salmon's hardiness, the Sacramento River has been so severely altered from its natural state by dam-building and water diversions that it can no longer support self-sustaining runs of salmon.

"What [salmon] require is pretty simple," he says. "Sufficient cold water must flow unimpeded from the mountains to the ocean during the appropriate season. The fact that salmon populations are declining dramatically throughout the Central Valley indicates how badly our thirst for water has overtaxed the capacity of our rivers to support wild salmon populations."

Gov. Brown has told reporters that the canal, which is now being designed as part of the Bay Delta Conservation Plan and which could be in operation within several years, will cost $15 billion. But others have second-guessed the governor and believe the water conveyance project could cost state voters as much as $50 billion or more.

Other critics have made the case that the "Peripheral Canal" could be illegal. In 1992, the Central Valley Project Improvement Act was passed, requiring that the federal government, in words from the Fish and Wildlife Service's website, "protect, restore, and enhance fish, wildlife, and associated habitats in the Central Valley and Trinity River basins of California." Conservationists say this law has been continuously broken for 20 years, and that the "Peripheral Canal" will only further the deterioration of Sacramento River native fishes habitat.

Gonella asserts that people must not be deceived by the summer's great salmon fishing into believing the fishery is healthy and stable.
"We're having a great year, and they're expecting a great year next year," Gonella says. "But people don't realize that if we don't get this right, it's game over. The salmon will be gone."